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ldd.c revision 1.18
      1 /*	$NetBSD: ldd.c,v 1.18 2011/03/29 20:56:35 joerg Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Paul Kranenburg.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 /*
     33  * Copyright 1996 John D. Polstra.
     34  * Copyright 1996 Matt Thomas <matt (at) 3am-software.com>
     35  * All rights reserved.
     36  *
     37  * Redistribution and use in source and binary forms, with or without
     38  * modification, are permitted provided that the following conditions
     39  * are met:
     40  * 1. Redistributions of source code must retain the above copyright
     41  *    notice, this list of conditions and the following disclaimer.
     42  * 2. Redistributions in binary form must reproduce the above copyright
     43  *    notice, this list of conditions and the following disclaimer in the
     44  *    documentation and/or other materials provided with the distribution.
     45  * 3. All advertising materials mentioning features or use of this software
     46  *    must display the following acknowledgement:
     47  *      This product includes software developed by John Polstra.
     48  * 4. The name of the author may not be used to endorse or promote products
     49  *    derived from this software without specific prior written permission.
     50  *
     51  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     52  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     53  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     54  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     55  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     56  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     57  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     58  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     59  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     60  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     61  */
     62 
     63 #include <sys/cdefs.h>
     64 #ifndef lint
     65 __RCSID("$NetBSD: ldd.c,v 1.18 2011/03/29 20:56:35 joerg Exp $");
     66 #endif /* not lint */
     67 
     68 #include <sys/types.h>
     69 #include <sys/mman.h>
     70 #include <sys/wait.h>
     71 
     72 #include <dirent.h>
     73 #include <err.h>
     74 #include <errno.h>
     75 #include <fcntl.h>
     76 #include <stdarg.h>
     77 #include <stdio.h>
     78 #include <stdlib.h>
     79 #include <string.h>
     80 #include <unistd.h>
     81 #include <ctype.h>
     82 
     83 #include "debug.h"
     84 #include "rtld.h"
     85 #include "ldd.h"
     86 
     87 /*
     88  * Data declarations.
     89  */
     90 static char *error_message;	/* Message for dlopen(), or NULL */
     91 bool _rtld_trust;		/* False for setuid and setgid programs */
     92 Obj_Entry *_rtld_objlist;	/* Head of linked list of shared objects */
     93 Obj_Entry **_rtld_objtail = &_rtld_objlist;
     94 				/* Link field of last object in list */
     95 u_int _rtld_objcount;		/* Number of shared objects */
     96 u_int _rtld_objloads;		/* Number of objects loaded */
     97 
     98 Obj_Entry *_rtld_objmain;	/* The main program shared object */
     99 size_t _rtld_pagesz;
    100 
    101 Search_Path *_rtld_default_paths;
    102 Search_Path *_rtld_paths;
    103 Library_Xform *_rtld_xforms;
    104 
    105 static void usage(void) __dead;
    106 char *main_local;
    107 char *main_progname;
    108 
    109 static void
    110 usage(void)
    111 {
    112 	fprintf(stderr, "Usage: %s [-f <format 1>] [-f <format 2>] <filename>"
    113 		" ...\n", getprogname());
    114 	exit(1);
    115 }
    116 
    117 int
    118 main(int argc, char **argv)
    119 {
    120 	const char *fmt1 = NULL, *fmt2 = NULL;
    121 	int c;
    122 
    123 #ifdef DEBUG
    124 	debug = 1;
    125 #endif
    126 	while ((c = getopt(argc, argv, "f:o")) != -1) {
    127 		switch (c) {
    128 		case 'f':
    129 			if (fmt1) {
    130 				if (fmt2)
    131 					errx(1, "Too many formats");
    132 				fmt2 = optarg;
    133 			} else
    134 				fmt1 = optarg;
    135 			break;
    136 		case 'o':
    137 			if (fmt1 || fmt2)
    138 				errx(1, "Cannot use -o and -f together");
    139 			fmt1 = "%a:-l%o.%m => %p\n";
    140 			break;
    141 		default:
    142 			usage();
    143 			/*NOTREACHED*/
    144 		}
    145 	}
    146 	argc -= optind;
    147 	argv += optind;
    148 
    149 	if (argc <= 0) {
    150 		usage();
    151 		/*NOTREACHED*/
    152 	}
    153 
    154 	for (; argc != 0; argc--, argv++) {
    155 		int fd;
    156 
    157 		fd = open(*argv, O_RDONLY);
    158 		if (fd == -1) {
    159 			warn("%s", *argv);
    160 			continue;
    161 		}
    162 		if (elf_ldd(fd, *argv, fmt1, fmt2) == -1
    163 		    /* Alpha never had 32 bit support. */
    164 #if defined(_LP64) && !defined(__alpha__)
    165 		    && elf32_ldd(fd, *argv, fmt1, fmt2) == -1
    166 #ifdef __mips__
    167 		    && elf32_ldd_compat(fd, *argv, fmt1, fmt2) == -1
    168 #endif
    169 #endif
    170 		    )
    171 			warnx("%s", error_message);
    172 		close(fd);
    173 	}
    174 
    175 	return 0;
    176 }
    177 
    178 /*
    179  * Error reporting function.  Use it like printf.  If formats the message
    180  * into a buffer, and sets things up so that the next call to dlerror()
    181  * will return the message.
    182  */
    183 void
    184 _rtld_error(const char *fmt, ...)
    185 {
    186 	static char buf[512];
    187 	va_list ap;
    188 	va_start(ap, fmt);
    189 	xvsnprintf(buf, sizeof buf, fmt, ap);
    190 	error_message = buf;
    191 	va_end(ap);
    192 }
    193 
    194 char *
    195 dlerror()
    196 {
    197 	char *msg = error_message;
    198 	error_message = NULL;
    199 	return msg;
    200 }
    201 
    202 void
    203 fmtprint(const char *libname, Obj_Entry *obj, const char *fmt1,
    204     const char *fmt2)
    205 {
    206 	const char *libpath = obj ? obj->path : "not found";
    207 	char libnamebuf[200];
    208 	char *libmajor = NULL;
    209 	const char *fmt;
    210 	char *cp;
    211 	int c;
    212 
    213 	if (strncmp(libname, "lib", 3) == 0 &&
    214 	    (cp = strstr(libname, ".so")) != NULL) {
    215 		int i = cp - (libname + 3);
    216 
    217 		if (i >= sizeof(libnamebuf))
    218 			i = sizeof(libnamebuf) - 1;
    219 		(void)memcpy(libnamebuf, libname + 3, i);
    220 		libnamebuf[i] = '\0';
    221 		if (cp[3] && isdigit((unsigned char)cp[4]))
    222 			libmajor = &cp[4];
    223 		libname = libnamebuf;
    224 	}
    225 
    226 	if (fmt1 == NULL)
    227 		fmt1 = libmajor != NULL ?
    228 		    "\t-l%o.%m => %p\n" :
    229 		    "\t-l%o => %p\n";
    230 	if (fmt2 == NULL)
    231 		fmt2 = "\t%o => %p\n";
    232 
    233 	fmt = libname == libnamebuf ? fmt1 : fmt2;
    234 	while ((c = *fmt++) != '\0') {
    235 		switch (c) {
    236 		default:
    237 			putchar(c);
    238 			continue;
    239 		case '\\':
    240 			switch (c = *fmt) {
    241 			case '\0':
    242 				continue;
    243 			case 'n':
    244 				putchar('\n');
    245 				break;
    246 			case 't':
    247 				putchar('\t');
    248 				break;
    249 			}
    250 			break;
    251 		case '%':
    252 			switch (c = *fmt) {
    253 			case '\0':
    254 				continue;
    255 			case '%':
    256 			default:
    257 				putchar(c);
    258 				break;
    259 			case 'A':
    260 				printf("%s", main_local);
    261 				break;
    262 			case 'a':
    263 				printf("%s", main_progname);
    264 				break;
    265 			case 'o':
    266 				printf("%s", libname);
    267 				break;
    268 			case 'm':
    269 				printf("%s", libmajor);
    270 				break;
    271 			case 'n':
    272 				/* XXX: not supported for elf */
    273 				break;
    274 			case 'p':
    275 				printf("%s", libpath);
    276 				break;
    277 			case 'x':
    278 				printf("%p", obj ? obj->mapbase : 0);
    279 				break;
    280 			}
    281 			break;
    282 		}
    283 		++fmt;
    284 	}
    285 }
    286 
    287 void
    288 print_needed(Obj_Entry *obj, const char *fmt1, const char *fmt2)
    289 {
    290 	const Needed_Entry *needed;
    291 
    292 	for (needed = obj->needed; needed != NULL; needed = needed->next) {
    293 		const char *libname = obj->strtab + needed->name;
    294 
    295 		if (needed->obj != NULL) {
    296 			if (!needed->obj->printed) {
    297 				fmtprint(libname, needed->obj, fmt1, fmt2);
    298 				needed->obj->printed = 1;
    299 				print_needed(needed->obj, fmt1, fmt2);
    300 			}
    301 		} else {
    302 			fmtprint(libname, needed->obj, fmt1, fmt2);
    303 		}
    304 	}
    305 }
    306 
    307 void
    308 _rtld_die(void)
    309 {
    310 	const char *msg = dlerror();
    311 
    312 	if (msg == NULL)
    313 		msg = "Fatal error";
    314 	xerrx(1, "%s", msg);
    315 }
    316 
    317 void
    318 _rtld_shared_enter(void)
    319 {
    320 }
    321 
    322 void
    323 _rtld_shared_exit(void)
    324 {
    325 }
    326 
    327 void
    328 _rtld_exclusive_enter(sigset_t *mask)
    329 {
    330 }
    331 
    332 void
    333 _rtld_exclusive_exit(sigset_t *mask)
    334 {
    335 }
    336